This proposal for the Washington D.C. Consortial Pediatric AIDS Clinical Trial Unit (PACTU) is a response to RFA-NIH-NIAID-91-AI-10. The consortial pediatric institutions include Children's Hospital (CH), a component of Children's National Medical Center, and Georgetown University Hospital for children and adolescents, working in collaboration with Howard University Hospital and D.C. General Hospital. (Howard University Hospital and D.C. General Hospital anticipate funding for HIV clinical trials from NICHD.) The consortial obstetrical programs include Georgetown University Hospital, Arlington Hospital, D.C. General Hospital, and the George Washington University Hospital. Collectively these institutions care for a large proportion of the HIV-infected children and pregnant women in Washington D.C. All programs have participated in clinical trials and CH is currently part of an NICHD PACTU. The consortial PACTU institutions are capable of recruiting approximately 50 pediatric and adolescent patients each year. The Principal Investigator will be located at CH. Primary Co-Investigators will be responsible for the project at the individual subunits. The Community Coordinator, Study Coordinator, Data Manager, and Data Entry Clerk will be located at CH. A single obstetrical Co-Investigator will coordinate the obstetrical studies. This Investigator has been conducting research on perinatal HIV at three of the proposed obstetrical services and CH for more than one year and is accruing about 20-25 new patients per year and therefore will have access to 25 or more pregnant HIV-infected women for potential entry into ACTG protocols.